Download or read book Identification of High Phosphorus Loss Areas in Agricultural Watersheds written by Katie Songer and published by . This book was released on 2009 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development and Validation of a Critical Source Area Index Tool to Identify Areas Vulnerable to Phosphorus Loss written by Emily Lesher and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Chesapeake Bay Watershed (CBW) has experienced water quality deterioration caused by diffuse agricultural phosphorus and nitrogen runoff entering the bay area. Agricultural decision support tools (DSTs) can help to not only improve commodity production, but also reduce pest and disease damage and reduce nutrient pollution. In the U.S. a commonly used DST is the Phosphorus Index (P Index), which is a field-based tool that identifies critical source areas (CSAs) vulnerable to P loss by evaluating source and transport factors; a high P-Index field would benefit from management changes to reduce P loss risk. An alternative approach is the identification of CSAs using high resolution landscape digital elevation models to identify within field intersections between high runoff potential and high soil phosphorus concentrations. Identifying CSAs as an approach for mitigating P loss from agricultural watersheds has revealed that often small portions of a watershed are responsible for the majority of pollutant loads. An example high resolution digital elevation model tool, the CSA Index, was developed in Ireland to target the most at-risk areas in a field for producing high runoff amounts and high P soils. The CSA Index is developed using plant available P measures like Mehlich-III P. However, studies investigating if forms of soil P beyond Mehlich-III extractable P should be monitored to reduce P losses are lacking. In this thesis I apply the CSA Index to four case study areas within the WE-38 sub-watershed of the greater CBW. The CSA Index generation was assessed using both a shallow soil sampling, 0- to 5- cm, and a standard agronomic sampling depth, 0- to 15- cm approaches at different depths. The results of the CSA Index are compared to the Pennsylvania P Index results run on each of the fields located within the case study areas to determine how areas vulnerable to P loss are identified and best management practice (BMPs) recommendations are made using each DST as a guide. I then performed intense sub-field scale soil sampling and re-run the CSA Index. These results were used to evaluate CSA Index results when soil P concentrations were derived from standard agronomic soil sampling and the more intensive sub-scale field sampling. Lastly, I examined different extraction approaches for measuring forms of phosphorus in the soil. I aimed to determine if forms of phosphorus vulnerable for runoff are missed by Mehlich-III P extraction methods and whether the presence or absence of a CSA influences the P concentrations. I found that the CSA Index and P Index differ in their identification of areas vulnerable to P loss. The P Index identified 15 out of 19 fields as being a "low risk" of P loss despite the CSA Index identifying CSAs in some of these "low risk" fields. The use of the CSA Index in combination with the P Index allowed for a discussion of BMPs for these case study areas. Recommendations to reduce P loss included extension of riparian buffers, crop conversion to permanent hay, and changes in field boundaries. It was determined that the best approach for applying BMPs to fields is to use the CSA Index initially to target CSAs on a smaller sub-field scale as well as identify flow pathways that may influence management changes. The P Index should then be used to drive management changes on the remaining landscape. Three of the four sub-watersheds saw an increase in CSA area at the 0- to 15- cm which resulted in more vulnerable areas of the landscape being identified at this deeper depth. The CSA Indices generated using the sub-scale soil sampling data showed that in all case study areas CSA are decreased with the more intensive sampling approach when compared to standard agronomic sampling. Despite the decrease in CSA area the agronomic sampling models still identified the majority of the most at-risk areas. The cost of performing sub-scale sampling as well as analyzing the data is a deterrent for using this sampling approach to run the CSA Index. For this reason and the fact that the models derived using agronomic sampling still succeeded in identifying CSAs it was suggested that soil P data determined using standard agronomic soil sampling be used to run the CSA Index. The evaluation of forms of phosphorus and methods used to measure them revealed that Mehlich-III P was a better predictor of total P than OP was and that Mehlich-III P concentrations increased exponentially as total recoverable 3050B P concentrations increased. Further investigation is needed to better understand the relationship between CSA and non-CSA areas and the forms of phosphorus present in the soils of these areas. Results from this thesis show how the use of the CSA Index in the CBW can further mitigate P loss from agricultural fields by precisely identifying within field CSAs that current DSTs like the P Index were not designed to identify. The widespread availability of LiDAR data across the region has dramatically reduced the cost of CSA Index development. Available soil testing data, or existing data ranges, could be used with LiDAR data to rapidly develop the CSA Index across CBW member states. The index should be evaluated in other physiographic provinces with less topographic driven surface hydrology to assess how it will perform in such landscapes. Future studies to validate the CSA Index should also include runoff monitoring of nutrient loads to adjacent waterbodies.
Download or read book Review of the New York City Watershed Protection Program written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2020-12-04 with total page 423 pages. Available in PDF, EPUB and Kindle. Book excerpt: New York City's municipal water supply system provides about 1 billion gallons of drinking water a day to over 8.5 million people in New York City and about 1 million people living in nearby Westchester, Putnam, Ulster, and Orange counties. The combined water supply system includes 19 reservoirs and three controlled lakes with a total storage capacity of approximately 580 billion gallons. The city's Watershed Protection Program is intended to maintain and enhance the high quality of these surface water sources. Review of the New York City Watershed Protection Program assesses the efficacy and future of New York City's watershed management activities. The report identifies program areas that may require future change or action, including continued efforts to address turbidity and responding to changes in reservoir water quality as a result of climate change.
Download or read book Phosphorus Loss from Soil to Water written by H. Tunney and published by Cabi. This book was released on 1997 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: Eutrophication, caused by phosphorus enrichment, is not a new environmental problem. The persistence of eutrophication in an era when many point-source phosphorus inputs have been curtailed has turned the focus of attention to agricultural phosphorus. A workshop was held in Ireland in 1995 to discuss factors controlling phosphorus losses to water from agriculture. This book presents the proceedings of the workshop and consists of 18 chapters by the invited speakers and three chapters with the 45 poster papers displayed at the workshop.
Download or read book Legacy Phosphorus in Agriculture Role of Past Management and Perspectives for the Future written by Luke Gatiboni and published by Frontiers Media SA. This book was released on 2021-01-07 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Floodplain Phosphorus Distribution in an Agricultural Watershed and Its Role in Contributing to In stream Phosphorus Load written by Iordanis Vlasios Moustakidis and published by . This book was released on 2016 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents an experimental study, both in the field and laboratory to cast more light on the primary role of the river floodplains in releasing and/or removing total-P to/from the in-stream load, under high runoff and flood conditions, by investigating the soil total-P spatial and vertical deposition patterns and topsoil erodibility, along the three (3) main river sections (e.g., headwaters, transfer and deposition zones) of an agricultural watershed, such as the Turkey River (TR). In soils, phosphorus, P, primarily exists as sediment-bound and less often as dissolved. During wet hydrological years, soil erosion and surface runoff are the main P release and transport mechanisms, while during dry hydrological years, P leaches to the deeper soil levels and is transported to freshwaters through groundwater discharge. In between the upland areas and the river network, there is a buffer zone, known as floodplain that regulates the flux exchanges between these two watershed components. Floodplains play an essential role in the riverine system health by supporting important physical and biochemical processes and improving the water quality downstream. These characteristics have led to the conclusion that floodplains primarily act as sinks for P. However, floodplains are subject to erosion as well, where soil particles along with the attached P are removed from the topsoil or enter re-suspension, under high runoff and flood conditions. The study provides an insight into the soil total-P deposition patterns across the floodplains of five (5) identified field sites and couples them with topsoil erodibility to eventually address the research objectives, which can be summarized as follows: (i) investigation of the soil total-P spatial and vertical variability across the floodplains along the main river zones and development of relationships between P variability and soil physical properties (e.g. soil texture); (ii) identification and characterization of the soil total-P deposition patterns across the floodplains (e.g., short- vs. long-term P deposition areas); and (iii) comparisons of the soil total-P concentrations and critical shear stresses among the main river zones and determination of their primary function either as P sources or sinks, under high runoff and flood conditions.
Download or read book Linking Critical Source Areas of Phosphorus to Stormflow Dynamics in Three Central Illinois Agricultural Watersheds written by Derek Evans and published by . This book was released on 2013 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: Critical Source Areas (CSAs) of phosphorus (P) are areas within a watershed that have a high propensity to export P to surface waters. CSAs contain two factors: source and transport factors. Source factors include soil P status and fertilizer and manure inputs, while transport factors include hydrologic and erosion processes that mobilize P. The aim of this study was to: 1) identify CSAs of P in an agricultural watershed and the stormflow dynamics controlling P export and 2) to delineate CSAs of P at the agricultural field scale using georeferenced soil test P (STP) and a digital elevation model (DEM) in a geographic information system (GIS). Soil test P (STP) along with dissolved reactive P (DRP), particulate P (PP), and total P (TP) in soil water, groundwater, and surface runoff were monitored in three small (
Download or read book Clean Coastal Waters written by National Research Council and published by National Academies Press. This book was released on 2000-08-17 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt: Environmental problems in coastal ecosystems can sometimes be attributed to excess nutrients flowing from upstream watersheds into estuarine settings. This nutrient over-enrichment can result in toxic algal blooms, shellfish poisoning, coral reef destruction, and other harmful outcomes. All U.S. coasts show signs of nutrient over-enrichment, and scientists predict worsening problems in the years ahead. Clean Coastal Waters explains technical aspects of nutrient over-enrichment and proposes both immediate local action by coastal managers and a longer-term national strategy incorporating policy design, classification of affected sites, law and regulation, coordination, and communication. Highlighting the Gulf of Mexico's "Dead Zone," the Pfiesteria outbreak in a tributary of Chesapeake Bay, and other cases, the book explains how nutrients work in the environment, why nitrogen is important, how enrichment turns into over-enrichment, and why some environments are especially susceptible. Economic as well as ecological impacts are examined. In addressing abatement strategies, the committee discusses the importance of monitoring sites, developing useful models of over-enrichment, and setting water quality goals. The book also reviews voluntary programs, mandatory controls, tax incentives, and other policy options for reducing the flow of nutrients from agricultural operations and other sources.
Download or read book Phosphorus Legacies and Water Quality Risks written by Tamara Van Staden and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Excess phosphorus (P) loading increases the frequency of harmful algal blooms (HABs), posing severe threats to drinking water security and aquatic ecosystems. Efforts to reduce the inputs of P to Canadian agricultural soils started in the late 1970s-early 1980s, and were initially successful, but surface water P loading became persistent again in the 2000s. HABs were a problem in the southern Laurentian Great Lakes (LGL) before the initial nutrient mitigation efforts, and the re-emergence of HABs in Lake Erie in the 2000s was in part a result of legacy P that had accumulated in soils and groundwater in agricultural watersheds. Legacy P exists as a result of historical inputs of P, typically fertilizer used in excess of crop needs. Consequentially, even after reducing P inputs, legacy P continues to be exported from soils after several decades. In Chapter 2, a large-scale mass balance was conducted for the Ontario watersheds to locate and quantify agricultural and other anthropogenic P inputs from 1961 to 2016, utilizing existing datasets as well as historical reconstructions of P inputs to the landscape. This scale of P mass-balance has not been completed before in Ontario. The mass balance model was implemented into a Geographical Information System (GIS) platform to delineate potential areas with legacy P accumulation and depletion within the landscape. These maps identified areas with high P inputs and large potential stores of legacy P. Historically, southwestern Ontario has had the densest agriculture and populated areas in Ontario and has had high P inputs over time. County-scale trends such as shifts to intensive livestock or crop-based agriculture, or increasing urbanization were also identified. In Chapter 3, the fate and transport of P and the possible development of P legacies was explored in the context of risk. P export is influenced by environmental conditions in soil, as such, there is spatial variance in the likelihood that P will runoff or accumulate in soils. The environmental conditions may therefore be used to represent the vulnerability of the system and the risk to either lose or accumulate P. The cumulative agricultural P surplus map was used in conjunction with vulnerability maps to construct soil P risk maps. Different vulnerability models were explored, and ultimately soil erosion potential maps were used to identify vulnerable areas with a high risk of P losses to surface water and areas with a high risk of P accumulation in soil. It was determined that there was a higher risk of P accumulation in soil along the coast of Lake Erie, and it is possible that P legacies exist in these areas. The results inform nutrient management and abatement strategies and the adaptive implementation of conservation practices.
Download or read book Flux and Sources of Nutrients in the Mississippi Atchafalaya River Basin written by and published by . This book was released on 1999 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Targeting High Phosphorus Loss Areas in the Spavinaw Creek Basin written by Daniel E. Storm and published by . This book was released on 2005 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measuring and Modeling Watershed Phosphorus Loss and Transport for Improved Management of Agricultural Landscapes written by Jacques Finlay and published by . This book was released on 2019 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Land Use and Hydrophysical Drivers on Temporal and Spatial Variability of Phosphorus and Nitrate Export in an Agricultural Subwatershed in Southern Ontario Canada written by Cameron A. Irvine and published by . This book was released on 2018 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt: The eutrophication of streams and lakes has been a long recognized problem in North America, particularly in Lake Erie where harmful and nuisance algal blooms have had many deleterious effects on aquatic ecosystems. Non-point source (NPS) pollution from agriculture has been identified as a key contributor of excess nutrients, namely phosphorus (P) and nitrogen (N), in the Great Lakes basin. There remains a need for increased understanding of the processes and drivers of nutrient losses from agricultural watersheds in order to better limit the negative influence of excess nutrients on receiving water bodies. Much of the existing research on agricultural nutrient export has focused on the growing season and there is a need to better characterize the seasonality of nutrient processes, as well as understand the important nutrient transport pathways. The objectives of this research were to identify key source areas ('hot spots') and peak periods ('hot moments') of nutrient export in an agricultural watershed and to draw inferences between the observed nutrient export and sub-catchment land use and practices. This research also characterizes the role of antecedent moisture conditions (AMC), event size, discharge, and flowpath contributions as potential drivers of the spatial and temporal variability in nutrient loads and concentrations. Streamflow and water chemistry were monitored over a 16-month period at four sites with differing land uses, in the Hopewell Creek watershed in Southern Ontario. The western lobe of the watershed was observed to be the 'hot spot' for P loads during all seasons, while temporally, the early spring snowmelt period was identified as the 'hot moment' throughout the watershed. The area of the watershed with the highest proportion of tile-drained land did not correspond to the P 'hot spot', and was instead an area with high peak flows and livestock operations. Flowpath contributions were shown to be an important driver of total phosphorus (TP) concentrations and nitrate (NO3-) loads through stepwise multiple linear regressions. This research emphasizes the importance of year-round event based monitoring programs for estimating nutrient export and further, that subwatershed scale studies can be used to identify nutrient hot spots in an agriculturally dominated catchment with spatially variable land use practices. Flowpath contributions were found to be important drivers of nutrient dynamics and this suggests that understanding flowpath contributions in agricultural subwaterheds can increase the predictive power for nutrient export models.
Download or read book Estimation of Agricultural Soil Erosion and Surface Water Quality Trends in the Cheney Lake Watershed written by Austin Bontrager and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Phosphorus and sediment runoff are the primary cause of eutrophication in Cheney Lake, the primary water source for Wichita, Kansas. Best Management Practices (BMPs) such as no-till farming practices and nutrient management can be implemented to reduce phosphorus runoff on high-risk agricultural fields. Past efforts have established BMP use in this watershed, although the effectiveness of these efforts has not been evaluated. The goals of this project were to identify any existing water quality trends in the Cheney Lake watershed, estimate the current distribution of erosion in the watershed, and evaluate the placement of BMPs with regards to field-scale erosion risk. Parametric, multi-linear regression and non-parametric, seasonal Mann-Kendall analyses were used to identify trends in the Total Suspended Solids (TSS) and Total Phosphorus (TP) of grab samples from the North Fork Ninnescah River. A Geographic Information System (GIS) model based on the Revised Universal Soil Loss Equation (RUSLE) was used to estimate watershed-scale erosion, prioritize agricultural land for BMP placement, and evaluate existing placement of BMPs within the Cheney Lake watershed. No detectible trends were identified in the water quality data due to stream variability, frequency of sampling, or absence of actual improvement in water quality. Additional sampling must be done to detect any trends in the future. BMPs were implemented on 13% of prioritized field area, and 11% of non-prioritized field area. Conservation Reserve Program (CRP) fields were placed on 14% of prioritized field area, and 5% of non-prioritized field area. No-till practices were implemented on 13% of prioritized field area, and 18% of non-prioritized field area. The top 20% eroding fields were identified given current conditions, and account for approximately 56% of the watershed-wide erosion. The GIS method has demonstrated utility in evaluating past erosion control measures for the watershed and in informing future decisions concerning BMP placement.
Download or read book Assessing Relative Risk of Long term Phosphorus Loss at Field Scale Using Proposed Modified Ontario P Index written by Parisa Pirouzan and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Nutrients originating from agricultural watersheds are known drivers of water quality impairment by causing eutrophication. The recently modified Ontario Phosphorus index (PLATO) is one P loss risk assessment tool to identify the areas vulnerable to P loss. Applicability and accuracy of PLATO is being tested in this study at two sites in Southwestern Ontario at field/intra-field scales. The main objective of this study is to identify the critical source areas to P loss within the Gully Creek watershed using this modified P index. Other P loss risk assessment tools (NCPLAT, APLE) are compared to enhance the results certainty at watershed level. The study also evaluates the spatial distribution of P loss risk within a field in the Bayfield river basin. The results indicate that at both field and sub-field scales the dominant P loss process in the rolling topography studied is particulate P through soil erosion loss.
Download or read book Nonpoint Source Stream Nutrient Level Relationships written by James M. Omernik and published by . This book was released on 1979 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Phosphorus Polluter and Resource of the Future written by Christian Schaum and published by IWA Publishing. This book was released on 2018-03-15 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive book provides an up-to-date and international approach that addresses the Motivations, Technologies and Assessment of the Elimination and Recovery of Phosphorus from Wastewater. This book is part of the Integrated Environmental Technology Series.
